The spider rests on a branch next to the web and enters/exits the web on separate threads (see these at about 9:30). I tried to shoot this the other day, w/o the spider in the web. AF didn't help. I tried today, again w/o the spider, using "AF Point select". I couldn't see the tiny trapped fly to focus on it. I turned off AF and IS, manually focused on the web, and started getting results. With gentle prompting I got the spider to run out to web center. It refused to pose better than this. This was my best shot.